Love/Hate series by Isabelle Richards

Opposites in every way, Chase and Arianna have been bitter rivals since childhood. Constantly in competition, they fight incessantly, making it nearly impossible for them to be in the same room with each other. Until they slept together.
Sex changes everything.
In one emotional evening, they go from enemies to lovers. Hate quickly evolves into passionate lust, but old habits die hard. The love growing between them can’t erase a lifetime of animosity. The two quickly fall back into old routines of spite and vengeance, and their relationship crumbles under the weight of their deep-seated distrust.
Chase and Arianna spend the next two years on opposite sides of the globe, avoiding each other at all costs. Despite the lies they tell themselves, neither one is ready to let go. Even though they are both engaged to other people, they can’t find it in their hearts to forgive each other or to move forward.
A family emergency calls Arianna home, where they have no choice but to face each other again. Will they finally admit the truth, or will they remain forever trapped between love and hate?